Microwave and millimeter-wave integrated circuits are essential to the functionality of wireless communication, radar, and imaging systems. Radar systems are important to military, automotive, and airborne vehicles where they may provide distance and velocity information of distant objects. Microwave and millimeter-wave-imaging methods such as radar may be relevant in medical and non-medical imaging applications in the near future such as cancer diagnostics, heart-rate monitoring, and gesture recognition.
Frequency Modulated Continuous Wave (FMCW) radar is a type of radar detection where a transmitted radar sine wave is swept in frequency around a center frequency. Typically the sweep is narrow in bandwidth, compared to the center frequency. Signals received, after being reflected by distant objects, are at a frequency that is no longer equal to the frequency currently being transmitted, due to the time delay for the electromagnetic wave to travel the range distance twice. The transmitter radar signal and receive radar signal are mixed to produce a low frequency signal whose frequency indicates the range of the target. Velocity information may also be deduced, using multiple frequency sweeps in succession, which may be increasing or decreasing in frequency.